Quench systems for cooling hot metallic components after removal from a heat treatment furnace, such as hot forgings or castings made from steel or aluminum alloys, are known in the art. As shown in FIG. 1, for instance, a typical forced air quench system 10 can often provide a flow of cooling air 90 from rotating fans located in a lower portion of the quench housing 20. The cooling air 90 flows upward from the fans and around, and some cases through, a plurality of metallic components 80 that are supported on a casting tray 60. As known to those of skill in the art, the casting tray 60 is generally a rigid metallic framework having a substantially open construction with large openings 64 defined by support ribs 62, and which is configured to maintain its shape during repeated thermal cycling through the hot furnace and subsequent cooling quench. The large openings 64 in the casting tray 60 can allow molding sand that falls out of the metallic components 80 during the heat treatment process to pass through the trays to lower sections of the heat treatment furnace (not shown), and then provide minimal obstruction for the cooling air 90 to flow upward, around and through the metallic components 80 after placement into the quench housing 20. In addition, the casting tray 60 is typically supported on a plurality of support rollers 32 of a roller conveyor 30 that moves the casting tray into and out of the quench housing 20, with the forced cooling air 90 from the fans flowing upward through gaps 34 between the rollers 32 prior to encountering the casting tray 60 and the metallic components 80 supported thereon.
Also illustrated in FIG. 1, the cooling air 90 typically flows upward from the fans at a predetermined and substantially uniform flow rate and speed across the entire width of the quench housing 20, to cool the metallic components 80 that are supported on the casting tray 60 in the center portion 22 of the housing. The flow rate of the cooling air 90 is generally determined by the size and speed of the fans and the cross-sectional area of the quench housing 20. In some installations the fans can be provided with variable speed drives that allow the flow rate to be increased or decreased depending on operating parameters, so as to quench the metallic components in accordance with a desired temperature profile or within a desired period of time. However, variable speed drives can add significant cost and complexity to the system, which can be undesirable. Although both the constant speed and variable speed versions of this generalized quench system design have proven adequate in many existing heat treatment installations, in some newer applications the flow rate of the cooling air 90 has been found insufficient for cooling larger and/or more complex metallic components within a desired time frame.
Consequently, a need exists for an improved forced air quench system and method that allows an operator to more efficiently cool larger and/or complex metallic components with a desired period of time. It is toward such an improved forced quench air system that the present disclosure is directed.